package thread;

import java.util.ArrayList;

public class Test {
    public static void main(String[] args) throws InterruptedException {
        ArrayList<Integer> list=new ArrayList<>();
        Thread t1=new Thread(){

                public   void run(){
                    for (int i=0;i<1000;i++){
                        synchronized (list){//锁临界对象，抢谁就锁谁
                            list.add(i);
                        }
                    }
                    }
                };
        Thread t2=new Thread(){
            public void run(){
                    for (int i=0;i<1000;i++){
                        synchronized (list){
                            list.add(i);
                        }
                    }
            }
        };
        t1.start();
        t2.start();
        Thread.sleep(4000);
        System.out.println(list.size());
    }
}
